Plasma cell with floating flange

Patent metadata

Field	Value
Publication number	US-9433070-B2
Application number	US-201414567546-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Dec 13, 2013
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A plasma cell for forming light-sustained plasma includes a transmission element configured to contain a volume of gas, a first terminal flange disposed at or near an opening of the transmission element, a second terminal flange disposed at or near another opening of the transmission element, a floating flange disposed between the first or second terminal flange and the transmission element. The floating flange is movable to compensate for thermal expansion of the transmission element. Further, the floating flange is configured to enclose the internal volume of the transmission element to contain a volume of gas within the transmission element. The transmission element is configured to receive illumination from an illumination source in order to generate plasma within the volume of gas. The transmission element is transparent to a portion of the illumination from the illumination source and a portion of broadband radiation emitted by the plasma.

First claim

What is claimed:

1. A system for forming a light-sustained plasma comprising:
an illumination source configured to generate illumination;
a plasma cell including:
a transmission element having one or more openings and configured to contain a volume of gas;
one or more terminal flanges disposed at or near the one or more openings of the transmission element;
one or more floating flanges disposed between at least one of the one or more terminal flanges and the transmission element, wherein the one or more floating flanges are movable to compensate for thermal expansion of the transmission element; and

a collector element arranged to focus the illumination from the illumination source into the volume of gas in order to generate a plasma within the volume of gas contained within the plasma cell,
wherein the plasma emits broadband radiation,
wherein the transmission element of the plasma cell is at least partially transparent to at least a portion of the illumination generated by the illumination source and at least a portion of the broadband radiation emitted by the plasma.

2. The system of claim 1 , further comprising:
one or more compressive elements disposed between the transmission element and the one or more floating flanges, the one or more compressive elements configured to compensate for thermal expansion of the transmission element.

3. The system of claim 2 , wherein the one or more compressive elements comprise:
one or more incompletely compressed seals.

4. The system of claim 1 , wherein the one or more floating flanges are formed from at a least one of a metal material or a ceramic material.

5. The system of claim 1 , wherein the one or more floating flanges include one or more coolant channels configure to flow coolant through the floating flange.

6. The system of claim 1 , wherein the one or more openings of the transmission element comprise:
a first opening at a first end of the transmission element; and
a second opening at a second end of the transmission element opposite the first end.

7. The system of claim 1 , wherein the transmission element has at least one of a substantially cylindrical shape or a substantially spherical shape.

8. The system of claim 1 , wherein the transmission element has a composite shape.

9. The system of claim 1 , wherein at least one of the one or more terminal flanges or the one or more floating flanges include:
one or more control elements.

10. The system of claim 9 , wherein the one or more control elements comprise:
at least one of an internal control element and an external control element.

11. The system of claim 9 , wherein the control element comprises:
at least one of a thermal control element, a convection control element, a plume control element, a gas fill control element and an ignition control element.

12. The system of claim 1 , wherein the plasma cell includes one or more feedthroughs.

13. The system of claim 12 , wherein the one or more feedthroughs pass through at least one of the one or more terminal flanges, the one or more floating flanges or one or more caps.

14. The system of claim 12 , wherein the one or more feedthroughs comprise at least one of a gas feedthrough, a cooling feedthrough or an electrical feedthrough.

15. The system of claim 1 , wherein the one or more terminal flanges comprise:
a first terminal flange disposed at or near a first opening; and
a second terminal flange disposed at or near a second opening.

16. The system of claim 15 , further comprising:
one or more connecting rods coupled to the first terminal flange and the second terminal flange and configured to secure the first terminal flange over the first opening and the one or more floating flange over the second opening.

17. The system of claim 16 , wherein the one or more connecting rods comprise:
one or more active connecting rods.

18. The system of claim 17 , wherein the one or more active connecting rods comprise:
one or more coolant transport rods configured to transport coolant between two or more of the first terminal flange, the second terminal flange, or the one or more floating flanges.

19. The system of claim 16 , wherein the one or more active connecting rods comprise:
one or more heat conduction rods.

20. The system of claim 19 , wherein the one or more heat conduction rods comprise:
one or more heat conduction rods configured to conduct heat between two or more of the first terminal flange, the second terminal flange, or the one or more floating flanges.

21. The system of claim 15 , further comprising:
one or more fins coupled to the first terminal flange and the second terminal flange and configured to secure the first terminal flange over the first opening and the one or more floating flange over the second opening.

22. The system of claim 21 , wherein the one or more fins are further configured to transfer thermal energy from a portion of the plasma cell to an ambient atmosphere.

23. The system of claim 1 , further comprising:
one or more radiation shielding elements.

24. The system of claim 23 , wherein the one or more radiation shielding elements comprise:
a radiation shield proximate to the one or more openings of the transmission element configured to block radiation from at least one of the illumination source and the radiation generated by the plasma from reaching one or more seals of the plasma cell.

25. The system of claim 23 , wherein the one or more radiation shielding elements comprise:
a coating layer proximate to the one or more openings of the transmission element configured to block at least a portion of the radiation generated by the plasma from reaching one or more seals of the plasma cell.

26. The system of claim 1 , wherein the transmission element is at least partially transparent to radiation between 120 nm and 200 nm.

27. The system of claim 1 , wherein the transmission element is at least partially transparent to radiation between 190 nm and 260 nm.

28. The system of claim 1 , wherein the transmission element is formed from at least one of calcium fluoride, magnesium fluoride, crystalline quartz, sapphire and fused silica.

29. The system of claim 1 , wherein broadband radiation emitted by the plasma further includes at least one of vacuum ultraviolet radiation, deep ultraviolet radiation, ultraviolet radiation and visible radiation.

30. The system of claim 29 , wherein the transmission element is at least partially transparent to at least one of vacuum ultraviolet radiation, deep ultraviolet radiation, ultraviolet radiation and the visible radiation.

31. The system of claim 1 , wherein the illumination source comprises:
one or more lasers.

32. The system of claim 31 , wherein the one or more lasers comprise:
one or more infrared lasers.

33. The system of claim 31 , wherein the one or more lasers comprise:
at least one of a diode laser, a continuous wave laser, or a broadband laser.

34. The system of claim 1 , wherein the gas comprises:
at least one of an inert gas, a non-inert gas and a mixture of two or more gases.

35. The system of claim 1 , wherein the collector element is arranged to collect at least a portion of the broadband radiation emitted by the generated plasma and di

Assignees

• Kla Tencor Corp

Inventors

• Bezel Ilya
• Shchemelinin Anatoly
• Torkaman Amir

Classifications

• H01J61/30 Primary

  Vessels; Containers · CPC title

• H01J65/04

  Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating {plasma display panels} · CPC title

• H05H1/24 Primary

  Generating plasma {(nuclear fusion reactors G21B1/00; gas-filled discharge reactors H01J37/32)} · CPC title

• H01J61/52

  Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space {(heating or cooling arrangements to promote ionisation for starting H01J61/54)} · CPC title